Point and adapter assembly

ABSTRACT

A wear assembly includes an adapter with a nose, a wear member with a socket to receive the nose, and a lock to secure the wear member to the adapter. The nose and socket include complementary rails and grooves that vertically diverge as they extend from the front of the nose. The lock can have a tapered construction.

FIELD OF THE INVENTION

The present invention pertains to a wear assembly, and especially to awear assembly for use with mining, excavating and earthmoving equipment.The inventive design is particularly well suited for an excavatingtooth, but may also be used for the support of other wear members.

BACKGROUND OF THE INVENTION

In mining and construction, wear members are typically provided alongthe digging edge of the equipment to protect the bucket or the likeand/or to engage and break up the ground to be gathered. Accordingly,the wear parts are subjected to highly abrasive conditions andexperience considerable wearing. The wear parts must then be replaced ona periodic basis.

In order to minimize the loss of material due to replacement of wornparts, the wear assemblies are typically manufactured as two or moreseparable components including an adapter and a wear member. The adapteris attached to the digging edge by welding, mechanical attachment, orbeing cast along an edge of the excavating device so as to present aforwardly projecting nose for supporting the wear member. The wearmember has a socket that is received over the nose, and a forwardworking end. In a point, the working end is typically a narrowed diggingedge. The wear member substantially envelops the adapter nose andthereby tends to protect the nose from wear. For example, depending on avariety of factors, generally five to twenty points can be successivelymounted on a single adapter before the adapter becomes worn and in needof replacement. To accommodate replacement of the wear member in thefield, the wear member is usually secured to the adapter nose by aremovable lock (e.g., a lock pin).

Wear assemblies used in mining, excavation and construction, andparticularly excavating tooth systems, are subjected to large and variedforces applied in all directions. As a result, points and other wearmembers must be firmly secured to the adapter to withstand the axial,vertical, reverse and lateral loads as well as impacts, vibrations andother kinds of forces. Vertical loads have been particularly troublesomein that large moment forces are generated that tend to “rotate” the wearmembers forward on the adapter and at times result in the ejection ofthe member. While the walls of the adapter nose provide support for thewear member, the lock in most cases also plays a large role in retainingthe point and resisting loads, particularly moment and reverse forces.

In a conventional tooth system 1 (FIG. 22), the adapter nose 2 andcomplementary socket 3 in the point 4 are wedge-shaped and includeconverging top and bottom surfaces 2 a, 2 b, 3 a, 3 b. A centraldownward load P applied at the free end 4 a of the point 4 will apply amoment force that tends to rotate the point 4 on the nose 2. The load Pis generally transmitted to and resisted by the upper side of the nosetip 2 c contacting the front end 3 c of the socket 3 (reaction force A)and by the lower side of a base portion 2 d of the nose contacting thebase or rear end 4 d of the point 4 (reaction force B). These reactionforces form a counteractive moment to resist the moment formed by forceP. As can be appreciated, large vertical forces can create substantialejection forces. Moreover, the impacts, vibration, wear, and presence offines, etc. exacerbate the difficulty of resisting high ejection forces.

In the present example of a central downward load P, the verticalcomponent of reaction force A, in general, equals the downward load Pplus the vertical component of reaction force B. However, because of theconverging walls of the nose, the horizontal component of each of thereaction forces A and B is in a forward direction that tends to urge thepoint off the nose. To the extent these forces are not resisted directlyby the geometry and friction of the nose and socket, they are resistedas shear loads by the lock pin. The repeated application of high shearloads can place unacceptably high stresses on the lock pin and result inits breakage.

Further, in such conventional teeth, the lock pin is typically hammeredinto place and tightly held by frictional forces applied primarily bythe placement of the holes in the point relative to the hole in theadapter nose. However, wearing of the point and adapter will tend toloosen the connection and increase the risk of losing the lock pin.Accordingly, the lock pin is often initially set very tightly in thedefined opening so as to put off the time when excessive loosenessdevelops. The lock pin must then be driven into and out of the openingby repeated blows of a large hammer. This can be a troublesome andtime-consuming task, especially in the larger sized teeth.

A take-up elastomer has often been placed in front of the lock pin in aneffort to maintain a tight fit between the point and adapter whenwearing begins to develop. While the elastomer functions to pull thepoint onto the adapter, it also reduces the lock's ability to resist theapplied moment and reverse forces. These loads tend to place more stresson the elastomer than it can withstand. As a result, during use,overworking of the elastomer can result in its premature failure andloss of the lock pin, which then results in loss of the point.

The loss of a point due to pin failure, looseness or elastomer problemsnot only results in premature loss of the point and wearing of theadapter nose, but also in possible damage to machinery that may beprocessing the excavated material, particularly in a mining operation.Moreover, since the adapter is often welded in place, replacement of anadapter usually results in significant down time for the diggingequipment.

A variety of different point and nose designs have been developed toincrease the stability of the point-adapter coupling, reduce the forcestending to eject the point, and lessen loading on the lock.

In one tooth design 1′ (FIG. 23) the front end of the nose 2′ and socket3′ are each provided with a squared configuration having upper and lowerstabilizing flats 5′, 6′. On account of the stabilizing flat 5′, acentral downward load P′ on the free end 4 c′ of the point 4′ will betransmitted to the nose tip 2 a′ so as to generate a vertical reactionforce A′ which generally has no substantial horizontal component tendingto eject the point from the nose. Nevertheless, the reaction force B′will still generate a substantial forward horizontal component at therear of the point that tends to push the point from the nose. While thisdesign improves the stability of the point over the conventional toothsystem, it still applies a substantial ejection force and can place highshear forces on the lock.

In another design, such as disclosed in U.S. Pat. No. 5,709,043 to Joneset al., the nose and socket are each provided with a front squaredsection and rear bearing surfaces that are substantially parallel to thelongitudinal axis of the tooth. In this construction, the combinedeffect of the front stabilizing flats and parallel bearing surfacescreate reaction forces at the tip and base of the nose that aregenerally only vertical. Such vertical reaction forces will in generalnot generate substantial horizontal components. Accordingly, thisconstruction greatly reduces the forces tending to push the point off ofthe adapter. Such stabilizing of the point also reduces shifting andmovement of the point on the adapter nose for reduced wearing.Nevertheless, multiple other factors (such as impacts, etc.) as well asreverse forces can still apply high shear forces to the lock.

In one other design, such as disclosed in U.S. Pat. No. 4,353,532 toHahn, the point and adapter are each provided with a helical turn orthread so that the point is rotated about its longitudinal axis whenmounted on the adapter nose. On account of the threads, the pointrotates about the longitudinal axis of the tooth and generally pressesthe lock against the adapter nose when ejection forces are applied. Thelock is much less likely to fail when under these kinds of compressionforces as opposed to the high shear forces applied in conventionalteeth. While this construction provides great strength and retentionbenefits, the nose and socket are complex and more expensive tomanufacture.

SUMMARY OF THE INVENTION

The present invention pertains to a wear assembly that provides a stablecoupling which is able to resist heavy loading without placing unduestress on the lock.

In one aspect of the invention, a wear assembly includes bearingsurfaces that are formed such that the wear member is tightened onto theadapter with the application of certain loads on the wear member. In onepreferred construction, the bearing surfaces are oriented such that thehorizontal components of reaction forces generated to resist, forexample, centrally applied vertical loads are directed rearward so as topush the wear member more tightly onto the adapter nose.

In another aspect of the invention, the wear member rotates on and offof the adapter about its longitudinal axis to better resist ejectionforces. In a preferred embodiment, the rotation is accomplished withgenerally linear rails and grooves that are easy and inexpensive tomanufacture. These complementary rails and grooves enable the assemblyto have a more slender profile than otherwise possible with helicalthreads for better penetration in excavation uses and less use of metal.Such grooves and rails also avoid the generation of high stress risersdue to the use of relatively sharp grooves used to form helical threads.

In another aspect of the invention, the adapter nose or socket of thewear member is formed with rails that diverge as they extend rearward.The complementary nose or socket then includes grooves that matinglyreceive the rails. In a preferred embodiment, the vertical divergence ofthe rails precludes an axial mounting of the wear member and requiresthe wear member to twist as it is moved onto or off of the adapter nose.

In another aspect of the invention, the adapter includes two bearingsurfaces positioned on opposite sides of the longitudinal axis andfacing in opposite directions. In a preferred embodiment, these bearingsurfaces reduce wear on the extreme fibers on the top and bottom of thenose. Moreover, the bearing surfaces are preferably formed as part ofrails on the adapter so as to form a generally Z-shaped cross-section.

In another aspect of the invention, the adapter nose and socket of thewear member widen as they extend forwardly. In a preferred embodiment,the adapter and socket include complementary rails and grooves thatdiverge to require twisting of the wear member during installation. Thisconstruction provides sufficient clearance to receive the forwardlywidened nose into the socket to better resist ejection of the wearmember.

In another aspect of the invention, the lock is tapered to fit into acomplementary channel to reduce frictional forces and ease the insertionand removal of the lock. In this configuration, the length of the lockdoes not frictionally slide through aligned openings, but rather engagesthe sides of the channel at or near the place of engagement. Hammeringof the lock as it is inserted or removed is avoided. In a preferredembodiment, the lock includes a lock member to secure the lock in thechannel to prevent unwanted loss or ejection.

The foregoing and other objectives, features, and advantages of theinvention will be more readily understood upon consideration of thefollowing detailed description of the invention, taken in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an excavating tooth system in accordancewith the present invention.

FIG. 2 is an exploded perspective view of the tooth system.

FIG. 3 is a front elevational view of an adapter for the tooth system.

FIG. 4 is a front view of the adapter nose only with the front bearingsurface parallel to the plane of the view.

FIG. 5 is a rear perspective view of a point for the tooth system.

FIG. 6 is a rear elevational view of the point.

FIG. 7 is a partial, top view of the tooth system.

FIG. 8 is a cross-sectional view of the tooth system taken along line8-8 in FIG. 7.

FIG. 9 is a side elevational view of the point positioned for mountingonto the adapter nose.

FIG. 10 is a partial cross-sectional view of the point mounted onto theadapter.

FIG. 11 is a vector force diagram of the tooth system in accordance withFIGS. 1 and 2.

FIG. 12 is a perspective view of an alternative embodiment of a toothsystem in accordance with the present invention.

FIG. 13 is a vector force diagram of the tooth system in accordance withFIG. 12.

FIG. 14 is a side elevational view of an adapter of another alternativeembodiment of a tooth system in accordance with the present invention.

FIG. 15 is an exploded perspective view of a second tooth system inaccordance with the present invention with an alternative lock.

FIG. 16 is a partial side view of the second tooth system with thealternative lock in its locking position.

FIG. 17 is a partial cross-sectional view taken along line 17-17 in FIG.16.

FIG. 18 is a perspective view of the alternative lock.

FIG. 19 is a rear view of the alternative lock engaged with a point ofan alternative tooth system.

FIG. 20 is a side view of another alternative lock inserted into a toothsystem.

FIG. 20 a is a perspective view of the lock shown in FIG. 20.

FIG. 20 b is a side view of the lock shown in FIG. 20.

FIG. 21 is a side view of another alternative lock inserted into a toothsystem.

FIG. 21 a is a perspective view of the lock shown in FIG. 21.

FIG. 21 b is a perspective view of the lock shown in FIG. 21 with thebase portions of the elastomer and detents shown in phantom.

FIG. 22 is a vector force diagram of a conventional tooth system.

FIG. 23 is a vector force diagram of another known tooth system.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is directed to a wear assembly for protecting awear surface. In particular, the wear assembly is especially adapted foruse in excavating, mining, construction and the like. The wear assemblyis well suited for use in forming an excavating tooth system, but couldalso be used to form other wear members.

For purposes of illustration, the present application describes theinventive construction as an excavating tooth system. The production ofother wear parts (e.g., a shroud) would utilize the same nose and socketconstructions, but could have different working and mounting ends. Forthe sake of description only, terms such as upper, lower, vertical, etc.are used in this specification and are to be understood as pertaining tothe tooth system as oriented in FIG. 1. The use of these terms is not anindication that these particular orientations are required for the wearassembly. The wear assembly could be oriented differently than asillustrated in FIG. 1.

In a preferred construction, a tooth system 10 comprises a point 12,adapter 14 and lock 16 (FIGS. 1-10). The adapter 14 preferably includesa forwardly projecting nose 18 and a mounting end 21 in the form of apair of rearwardly extending legs 22 (FIGS. 1, 2, and 9-10). The legs 22are adapted to straddle the digging edge 23 of an excavator and bewelded in place. However, the mounting end could be different to attachthe adapter in other ways, such as by a mechanical attachment or beingintegrally cast with the digging edge. In addition, especially in largeteeth, the adapter could be attached to a second adapter or the like,which is then secured to the digging edge.

The nose is generally wedge shaped and formed by converging walls 24,26, sidewalls 28, 30, and a front bearing surface 32. Bearing surface 32is adapted to receive axially directed loads applied to the wear member12. The converging walls 24, 26 are preferably formed with a gentletransverse curve for enhanced strength and durability (FIGS. 3 and 8),although they could be flat, provided with a greater curvature, orformed with another configuration. The sidewalls 28, 30 extend ingenerally parallel planes, although preferably with a slight taper.However, the sidewalls could be formed with a substantial inclination ifdesired. The transition edges between the converging walls and thesidewalls are generally rounded to minimize the concentration of stressat these locations.

The sidewalls 28, 30 of the nose 18 are each formed with a flank 34 anda rail 35 having an outer surface 36 and a lateral surface 37 (FIGS. 2,3, 4 and 9). In one preferred construction, while the rails 35 extendrearward in substantially parallel planes (i.e., with the rearwardextension of the sidewalls), they diverge from each other as they extendrearward. Specifically, one rail 35 a extends from bearing surface 32 ina rearward direction that is substantially parallel to the rearwardextension of converging wall 26, and one rail 35 b extends rearwardlyfrom bearing surface 32 in a direction that is substantially parallel toconverging wall 24. In this way, the rails 35 a and 35 b diverge ingenerally vertical directions as they extend rearward. The rails arepreferably formed with linear faces and generally constant depths andwidths, primarily for easier manufacturing. However, otherconfigurations are possible.

In a preferred construction, one rail extends adjacent and substantiallyparallel to each converging wall 24, 26. Accordingly, an outside edge ofeach converging wall 24, 26 defines the top or bottom of the adjacentrail while lateral surface 37 extends generally parallel to the rearwardextension of the converging wall. Nevertheless, variations are possible.For example, the lateral surfaces may have a non-linear shape or anextension that is not parallel to the converging wall. Further, therails may be spaced from the converging walls such that they could havea second lateral surface (not shown) apart from the converging walls 24,26.

The outer surface 36 of each rail 35 is substantially vertical.Preferably, the lateral surface 37 and flank 34 are inclined to form agenerally V-shaped recess 40 (FIGS. 3 and 8). Accordingly, the lateralsurface 37 and flank 34 each present a surface area that is transverseto vertical to form primary bearing surfaces for vertical and lateralloads applied to the point 12. The converging walls 24, 26 formsecondary bearing surfaces that may contact the socket under heavyloading or after wearing of the parts. Each lateral surface 37 ispreferably set at an angle of 75 to 115 degrees relative to itsrespective flank 34, and most preferably at an angle of 95 degrees.Nevertheless, other angles could be used. The flanks 34 are generallytriangular in shape such that they expand as they extend rearward toform an increasingly greater portion of each sidewall 28, 30.

The point 12 has a generally wedge-shaped configuration defined byconverging walls 43, 45 and sidewalls 47, 49 (FIGS. 1-10). Theconverging walls 43, 45 narrow to form a forwardly projecting diggingedge 51. A rearwardly opening socket 53 is provided to receive theadapter nose 18.

The socket 53 is preferably shaped to matingly receive the adapter nose18 (FIGS. 5, 6 and 8). Accordingly, the socket is defined by convergingsurfaces 55, 57, side surfaces 59, 61, and a front surface 63. Each sidesurface 59, 61 is formed with a groove 65 and an inwardly projectingridge or protrusion 67. The grooves 65 are shaped to receive the rails35 on the adapter nose. Hence, in the preferred construction, thegrooves 65 are preferably formed to extend along opposite convergingsurfaces 55, 57. The protrusions 67 each define a lateral surface 69 andan inner surface 71 that oppose and bear against lateral surface 37 andflank 34, respectively. Hence, lateral surface 69 and inner surface 71form primary bearing surfaces for generally vertically applied loads,whereas the converging surfaces 55, 57 form secondary bearing surfacesthat may contact the nose under heavy loading or after wearing of theparts. The front surface 63 is adapted to abut bearing surface 32 duringaxial loading.

While the nose is preferably on the adapter and the socket in the pointto minimize the amount of metal needed in the wear member, a rearwardlyextending nose could be provided on the point to be received in a socketdefined in the adapter. Also, the socket and nose constructions could bereversed so that internal rails (not shown) could be provided in thesocket with mating grooves provided on the nose (not shown).

On account of the diverging rails 35 and grooves 65, the point 12 mustbe turned or rotated as it is fit onto the adapter nose 18. In thepreferred construction, the point rotates on the order of an eighth of aturn as it is installed. As a result, the point fits onto the adapternose in much the same way as if the point and adapter were formed withhelical threads rather than with straight rails and grooves. The point12 is mounted to the nose 18 by first orienting the point 12 withrespect to the nose 18 so that the rear portion 73 of each groove 65 islocated adjacent to the front portion 75 of a corresponding rail 35 inorder to receive the rail, as shown in FIG. 9. Because the grooves arevertically diverging, the aligning of the front end of the rails withthe rear end of the grooves causes the point to be rotated relative toits final position. Hence, as the point is slid onto the nose, the pointis rotated about longitudinal axis X to provide ample clearance for therails, ultimately causing the rails 35 to be inserted into therespective grooves 65. FIG. 10 shows the point 12 mounted on the nose 18with the rails 35 fully inserted into the grooves 65 of socket 53.

The present invention thus achieves certain advantages provided by theearlier wear assemblies provided with helical threads (e.g., U.S. Pat.No. 4,353,532), but with a simpler and less expensive geometry tomanufacture. The opposing rails of the present invention are easier tocast than the helical thread assemblies. In addition, the use of largerrails and grooves instead of sharper helical grooves lowers the stressrisers in the nose for enhanced strength and durability.

The present invention also achieves other advantages over theconventional helical thread assemblies. The present invention does notuse a conical base for the nose, but rather uses a more slender profilewedge shape. Thus, the height of the nose (between the top and bottomsurface) is not restricted by a conical base, and therefore the heightof the nose may be adjusted according to need. The nose of the presentinvention may therefore be used to form tooth systems with more slenderprofiles than those provided with helical threads. The more slenderprofile tooth system provides for better penetration during digging andrequires less metal to make.

In addition, the degree of twist can be varied by changing the angledefining the divergence of the rails. In general, the greater the angle,the greater the amount of twist the point undergoes during installationand removal.

With this construction, the point 12 is stably positioned on the adapternose 18. As compared to a conventional tooth, a centrally appliedvertical load P1 on the free end 51 of the point 12 generates a smallerejection force on account of the horizontal components of the reactionforces A1 and B1 (FIG. 11). For example, a central downward load P1 onthe free end 51 of the point 12 generates reaction forces A1 and B1 atthe tip and base of the nose 18. The vertical component of reactionforce A1 is generally the same as the load P1 plus the verticalcomponent of reaction force B1. However, because the inclination of therail 35 resisting the upward motion of the rear or base end of the pointis in the opposite direction to the lower converging wall 45, thehorizontal component of reaction force B1 is rearwardly directed to pushthe point onto the adapter rather than eject it. This holding ortightening force then at least partially offsets the ejection force dueto the horizontal component of reaction force A1. While loads withvertical components applied to different parts of the point 12 may notalways create the noted tightening force, the effect will occur undernormal loads for a significant advantage.

In another preferred construction, the front free end 42 of the nose 18a is formed to have a generally rectangular configuration with upper andlower stabilizing flats 44, 46 (FIGS. 12 and 13). These flats 44, 46extend substantially parallel to the longitudinal axis of the tooth toprovide further support for stabilizing the point on the adapter,particularly in resisting vertically directed loads on the front end ofthe point 12 a. The substantially parallel flats may be inclined to thelongitudinal axis for up to about seven degrees for drafting purposes.While the flats may be inclined at greater angles, their stabilizingfunction tends to decrease with an increasing inclination. The socket 53a of point 12a includes a pair of front end stabilizing flats 78, 79that engage flats 44, 46 on the adapter nose 18 a. The front end of thesocket is preferably given a generally rectangular configuration to matewith the front end of the nose, although shapes other than rectangularfor the front ends of the nose and socket are possible.

In the preferred tooth system 10 a, a centrally applied downward load P2on the free end of the point 12 a creates a substantially verticalreaction force A2 with generally no horizontal component acting as anejection force (FIG. 13). As discussed above, the inclination of therails generate a horizontal component with a holding force at the baseend of the point rather than an ejection force. Hence, with this loadingthe overall effect of the bearing surfaces (i.e., the flats and therails) is to tighten the point on the adapter rather than eject it.

This construction provides a substantial improvement in point stability.The generation of the resultant tightening forces will lessen loading onthe lock pin and reduce the risk of point loss. The resultant tighteningforces will also tend to reduce the movement of the point on the adapternose, which in turn will reduce the wearing of the tooth construction.Moreover, because the system is tightened while under most predominantor normal vertical and axial loading, the manufacturing tolerances canbe loosened for easier and less expensive manufacturing, the use oftake-up style lock pins (with load bearing elastomers) can beeliminated, and gauging requirements can be reduced without shorteningthe useful life of the tooth. Instead, the tooth will have enhanceddurability.

In a conventional tooth system (see FIG. 22), the extreme fibers of theupper and lower converging walls 2 a, 2 b of the nose 2 (i.e., thosesurfaces spaced vertically farthest from the longitudinal axis) tend tohave high stress levels under vertical loading because of the tendencyof such loads to bend the nose. In conventional teeth, the outerconverging surfaces form the primary bearing surfaces as well asundergoing the highest stress levels. As a result, these surfaces moveand rub against the socket walls and experience a high degree of wearingunder heavy loading. In the present invention, the rails 35 and flanks34 form the primary bearing surfaces. Since the bearing surfaces arecloser to the central horizontal plane of the tooth system, wearing ofthese surfaces has less affect on the ability of the nose to withstandhigh bending loads than wearing of the outer converging walls. With lesswearing, the tooth system of the present invention is a stronger andmore durable assembly. As a result, a smaller tooth system made inaccordance with the present invention, which requires less metal and hasbetter penetration, can replace bigger conventional tooth systems.Moreover, this reduction of wear in the extreme fibers will enable thesection modulus to remain nearly the same throughout the life of thenose to maintain nose strength.

As an alternative, because of the rotation used to install and removethe tooth system, the front end of the nose and corresponding socket canactually be wider than the rear end of the nose; that is, the sidewallscan be tapered to diverge slightly at an angle up to about 5 degrees asthey extend forward. This expansion of the nose and socket widths at thefront of the nose will tend to restrict the paths for removing the pointfrom the nose to the designed rotation even as wearing occurs. As aresult, this construction provides increased resistance to forcestending to remove the point and especially reverse forces.

As another alternative, the nose can be provided with longitudinallyextending rails 80 that include outer faces 81 and lateral bearing faces83 (FIG. 14). The lateral bearing surfaces 83 are generally parallel toeach other and to the longitudinal axis X of the tooth. In thesearrangements, the depth of the rails preferably increases as the railsextend rearward; that is the converging walls of the nose form the upperor lower surfaces of the respective rails 80 even though the lateralsurfaces 83 extend rearwardly in an orientation that is generallyparallel to the longitudinal axis of the tooth. Nevertheless, the railscould have a constant depth and simply be spaced from the respectiveconverging wall. Without the divergence of the rails, the point is notrotated onto the adapter nose. While some of the benefits for having thepoint turn as it is installed and removed do not apply to thisembodiment, the rails still continue to provide a stabilizing surface(as compared to the conventional tooth system) that reduces the stressesin the extreme fibers of the converging walls and, as discussed above,reduces the wearing of the bearing faces on resisting the bendingforces. The use of only two rails that form a generally Z-shaped crosssection improves the noted loading and wearing benefits for a reducedamount of material. This embodiment can further be used when twisting ofthe point during installation is not desired or possible. As oneexample, the points could be welded to a plate and the assembly thenmounted collectively to the projecting adapter noses along the diggingedge.

In regard to all of the embodiments, the nose and points are preferablyformed to be rotationally symmetrical about the longitudinal axis X sothat the points can be reversibly mounted on the nose. Nevertheless,asymmetrical nose and/or points could be used in this invention.

The point and adapter assembly of the present invention can be used witha wide variety of different locks to resist removal of the point fromthe adapter. Because the lock 16 withstands compression forces at leastpartially in lieu of shear forces (and thus experiences reduced shearloading) in resisting the ejection of point 12 from nose 18, the lockneed not be as robust as locks used with other conventional point andadapter assemblies applying substantially only shear loads on the locks.The placement of the lock 16 is preferably along one side of the nose18, as shown in FIGS. 1 and 2. However, a lock could be provided atother locations including a vertical or horizontal central passage (suchas in conventional tooth systems). Further, virtually any conventionallock used to secure points to the adapters including solid lock pins,pins with take-up elastomers, or locks with rigid casings such asdisclosed in U.S. Pat. No. 5,469,648 to Jones et al. could be used inconjunction with this invention.

FIG. 2, for example, shows a lock 16 in the form of a drive through lockpin that is received in a vertical channel 89 in the side of the nose.As is known, the point is provided with at least one rearwardlyextending ear 91 having an inwardly extending lug 93 to engage the rearside of the pin and retain the point to the adapter. Preferably, an earand lug is provided on both sides of the point (not shown) so that thepoint can be reversible mounted in either of 180 degree positions. Whilethe channel and pin are shown with a linear configuration, they could becurved as in U.S. Pat. No. 4,965,945 to Emrich.

In the preferred construction, a tapered locking pin 16′ is provided tosecure the point to the adapter. Referring more particularly to FIGS.15-18, a nose 18′ has a tapered vertical channel 103 along one side forreceiving a tapered locking pin 16′. Although the lock can be taperedalong its entire length, it only needs to be tapered along a substantialportion of its length. In the preferred construction, the front surface104 gradually arcs rearward the entire length of the lock so that thetaper extends along substantially the entire length of the lock. FIG. 15shows a blind channel that extends only partially through the nose andtapers to a closed end 105 at the bottom. Nevertheless, an open channelthat extends entirely through the adapter could be used with the taperedpin if desired.

The locking pin 16′ has a corresponding tapered shape to fit within thetapered channel 103 (FIGS. 15-18). The locking pin 16′ preferablyterminates in a narrow point 106. The pin 16′ has a bearing portion 107that has a front surface 104 for engaging the shoulder 109 of the nose(i.e., the front edge of channel 103) and a rear surface for engagingthe lug 93′ of the ear 91′. In the embodiment shown in FIGS. 15-18, thelocking pin 16′ has a web 111 that extends rearward to strengthen thelock against axial forces and ensure proper insertion of the lock pin.However, the lock pin could have a uniform circular, rectangular orother shape as desired.

The nose 18′ defines a slot 113 in communication with the channel 103 toallow the lug 93′ and ear 91′ to pass along the side of the nose to aposition within the channel. The pin 16′ defines a recess 115 behind therear surface 107 and proximate to the web 111 for receiving a portion ofthe lug 93′. The locking pin 16′ may be formed from any conventionalmethod, such as by casting.

The lock pin 16′ is preferably retained in the channel 103 through theuse of a locking member. In the embodiment shown in FIGS. 15-18, thelocking member is a set screw 121. The channel 103 preferably includesan indent 125 for receiving the set screw to better retain the lockingpin in the channel 103, but the indent is not required. Once the lockpin 16′ is installed in the channel 103, the set screw 121 is tightened.The set screw 121 may be upset at the end or provided with a retainingring or other means to prevent the set screw from becoming disassociatedfrom the lock pin. The lock pin preferably includes an overhanging shelf123, which protects the set screw from wear. A spring (not shown) canalso be associated with the set screw to inhibit loosening duringvibration.

The lock pin 16′ could also be used in conjunction with other wearassemblies. For example, as shown in FIG. 19, the lock pin could be usedto retain a point 128 with a simple wedge shaped socket, ears 132, lugs130. A tapered lock pin in accordance with the present invention couldalso be used in tooth systems having vertical or horizontal centralholes (not shown).

Alternatively, other locking members may be provided, such as anelastomer backed detent to resist removal of the pin from the groove. Inaddition, while the embodiment of FIGS. 15-18 shows the locking membercoupling the lock pin to the adapter, the locking member may insteadoperably engage the locking pin to the point. In addition, the lockingmember need not be attached to the locking pin, but instead may be aseparate member or attached to the adapter or point (see, for example,the plug in U.S. Pat. No. 4,965,945).

As examples of alternatives, lock pins 131,133 (FIGS. 20-20 b, and 21-21b) have tapered constructions that could be used in place of lock pin16′. Lock pin 131 has a detent 134 that is biased outward at one end 136by an elastomer 138 to fit under a ledge 140 defined in the adapternose. The detent preferably has a projecting contact surface 136 a toform a secure engagement with ledge 140. The detent 134 is preferablyadhered to elastomer 138 which in turn is adhered in a pocket of thecast body 135. In lock pin 133, the detent 141, is biased to move alongan arcuate path 143 by an elastomer 145. The free end 147 of the detent141 engages a notch 149 or the like defined in the adapter nose. In eachcase, the adapter nose includes a narrow slot (not shown) whereby a toolcan be inserted to push the detents into the elastomers to release thedetents 134, 141 when removal of the locks is desired.

One of the advantages of a tapered pin is that it is easier to installand remove than a conventional drive-through pin. The tapered surfacesallow the locking pin to be inserted without encountering any resistancefrom the surface of the point or nose until the locking pin is almostentirely inserted into the channel. The tapered locking pin may beremoved using a pry tool, rather than being hammered because the pinneed only travel a short distance before it is free from the channel.Once free, the lock pin may be removed by hand. In contrast, with aconventional drive-through lock pin, the two bearing surfaces of the pinare nearly parallel in order to ensure good bearing contact between thepoint and the nose. Consequently, the drive-through locking pinencounters significant resistance along the entire distance of travel asit is inserted into or removed from the wear assembly.

Another advantage of the tapered lock pin of the present invention isthat the force required to remove the lock with the lock member engagedis greater than that required to remove a conventional drive-throughlocking pin. The tapered locking pin is prevented from moving downwardbecause the groove narrows or terminates, and the locking member, suchas the set screw, prevents the lock pin from moving upward out of thegroove. The lock pin thus relies on mechanical interference, rather thana tight fit, to prevent removal of the tapered locking pin onceinstalled.

The above discussion concerns the preferred embodiments of the presentinvention. Various other embodiments as well as many changes andalterations may be made without departing from the spirit and broaderaspects of the invention as claimed.

1-128. (canceled)
 129. A wear assembly comprising: an adapter having arear mounting end for securing the assembly to a wear surface and aforwardly extending nose having a pair of rails; a wear member defininga longitudinal axis and including a pair of converging walls extendingto a narrowed front working end, a pair of sidewalls, and a rearwardlyopening socket having a pair of grooves each on opposite sides of thesocket for receiving the rails, wherein each groove diverges from aplane aligned with the longitudinal axis and extending along thenarrowed front working end; and a lock for securing the wear member tothe adapter.
 130. A wear assembly in accordance with claim 129 in whicha front end of the socket includes opposed front bearing surfacesextending between the opposite sides of the socket, and each of thefront bearing surfaces extends generally parallel to the longitudinalaxis.
 131. A wear assembly in accordance with claim 129 in which eachgroove has a substantially constant width and depth along substantiallyits entire length.
 132. A wear assembly in accordance with claim 129 inwhich the groove extend along substantially parallel planes alignedgenerally along the sidewalls of the wear member.
 133. A wear assemblyin accordance with claim 129 in which the wear member is a point and thenarrowed working end is a digging edge.
 134. A wear member defining alongitudinal axis and including a pair of converging walls extending toa narrowed front working end, a pair of sidewalls, and a rearwardlyopening socket for receiving a nose of an adapter, the socket having agroove on each of a pair of opposite sides of the socket for receivingrails on the adapter nose, wherein each groove diverges from a planealigned with the longitudinal axis and extending along the narrowedfront working end.
 135. A wear member in accordance with claim 134 inwhich a front end of the socket includes oppose front bearing surfacesextending between the opposite sides of the socket, and each of thefront bearing surfaces extends generally parallel to the longitudinalaxis.
 136. A wear member in accordance with claim 134 in which eachgroove has a substantially constant width and depth along substantiallyits entire length.
 137. A wear member in accordance with claim 134 inwhich the grooves extend along substantially parallel planes alignedgenerally along the sidewalls.
 138. A wear member in accordance withclaim 134 in which the wear member is a point and the narrowed workingend is a digging edge.
 139. A wear member comprising a front end, asocket having an open rear end to receive a nose fixed to an excavatingmachine, the socket being defined by converging surfaces, side surfaces,a front surface and the open rear end, and having a longitudinal axis,and a lateral surface positioned between the front surface and the openrear end of the socket that faces in a direction generally toward one ofthe converging surfaces, the lateral surface being inclined to thelongitudinal axis to produce in use a resisting force having a componentthat tends to pull the wear member rearward onto the nose for certainloads applied to the front end of the wear member.
 140. A wear member inaccordance with claim 139 wherein the lateral surface is inclinedrelative to the longitudinal axis in the same general direction as theconverging surface toward which the lateral surface generally faces.141. A wear member in accordance with claim 139 wherein the lateralsurface extends along one of said side surfaces of the socket.
 142. Awear member in accordance with claim 139 further comprising two saidlateral surfaces, wherein a first of said lateral surfaces facesgenerally toward a first of the converging surfaces, and a second ofsaid lateral surfaces faces toward a second of the converging surfaces.143. A wear member in accordance with claim 142 wherein the first andsecond lateral surfaces are along opposite side surfaces.
 144. A wearmember in accordance with claim 143 wherein each said lateral surfaceextends from the front surface to the rear end of the socket.
 145. Awear assembly comprising: a wear member having a front end, a sockethaving an open rear end to receive a nose fixed to an excavatingmachine, the socket being defined by converging surfaces, side surfaces,a front surface and the open rear end, and having a longitudinal axis,and a lateral surface positioned between the front surface and the openrear end of the socket that faces in a direction generally toward one ofthe converging surfaces, the lateral surface being inclined to thelongitudinal axis to produce in use a resisting force having a componentthat tends to pull the wear member rearward onto the nose for certainloads applied to the front end of the wear member; a nose receivedwithin the socket; and a lock to releasably secure the wear member tothe nose.
 146. A wear assembly in accordance with claim 145 wherein thenose has a lateral surface to engage each said lateral surface of thewear member.
 147. A wear assembly in accordance with claim 146 whereineach said lateral surface of the nose extends along a sidewall of thenose.
 148. A wear assembly in accordance with claim 147 wherein eachsaid lateral surface of the nose is inclined to the longitudinal axis inthe same direction as the lateral surface of the wear member which itengages.